In robot-controlled production of fiber reinforced plastic products, fiber thread pieces are fed out into a molding cavity while being oriented, so that the strength of the fibers is utilized efficiently in the finished product. Compressed air is used for the transport of the cut fiber pieces from the cutter to the molding cavity.
If the pressure/speed of the compressed air is not sufficiently high at the center, static electricity will make fiber pieces stick to the vicinity of the cutter, so that the feeding out is stopped up. This may be economically seriously damaging if the operations at a production line, which depends upon the plastic details, is also influenced by the production loss.
However, if air pressure/speed is too high at the molding cavity, fiber pieces may be oriented wrongly in the cavity, simply by being blown away from their intended location, or because they are deflected from the mold surface by having too high kinetic a energy.
These problems can be reduced if it is possible to maintain an optimal distance between the feed out apparatus and the molding cavity. However, this is hardly ever possible, e.g. because of lack of space.